Heat regenerators



Oct. 7, 1958 IRWIN HEAT REGENERATORS 3 Sheets-Sheet 1 Filed May 25. 1953 FIG. I

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IN V EN TOR.

United StatcS' Ptenf 4 Claims.` (Cl. 263-51) This invention is a heat regenerator, of the chimney type, particularly adapted foruse in connection with steel making. The drawings show its application to regenerative open hearth furnaces. It may also be applied to blast furnace stoves. 'It has the advantage of providing more returned heat in the form of a higher temperature which speeds up furnace production right aftereach reversal. It also permits the use of a dust blowing tool/7' inside the regenerator of an open hearth furnace. 'The/ drawings here show the application of this invention to/ the regenerators of an open hearth furnace.

A specific example of the invention is illustrated by the accompanying drawings, the various figures being as follows:

Figure 1 is a horizontal section from line I-I in Figure 2 and shows the positions of two refractory inserts on its top;-

Figure 2 is a vertical section from lines II-II in the same vertical plane in the Figures l, 3 and 4;

Figure 3 is a horizontal section from line III-III in Figure 2 and shows the positions of two refractory inserts on its top;

Figure 4 is a horizontal section from line IV-IV in Figure 2;

Figures 5 and 6 are respectively the plan and side views of a special refractory brick;

Figures 7 and 8 are respectively the plan and side views of a common refractory brick;

Figures 9 and 10 are respectively the plan and side views of a special refractory insert;

Figures 11 and 12 are respectively the plan and side views of a modification of the special refractory insert;

Figure 13 is a chimney passage of Figure 2 showing the application of the said two forms of refractory inserts;

Figures 14 and 15 are respectively the plan and side views of a modification of the special refractory brick;

Figure 16 is an assembly of the modification of the special refractory bricks;

The items 1, 2, 3 and 14 respectively have any horizontal cross-section to be the same as its plan view. Item 13 is the same as item 3 with a bottom extension of the same uniform thickness as the part above it.

A common refractory brick iS a solid and has the geometrical form known as a rectangular parallelepiped.

These drawings show a heat regenerative chamber and its heat regenerator for an open hearth furnace as an example for describing this invention.

In Figure 2 the hot gases come in through the top horizontal passage of the regenerative chamber and go down through the three chimney groups 5, 6 and 7 t0 the bottom horizontal passage of the regenerative chamber -and then out to the stack. The reverse flow takes place for the air or fuel gas and heat is transferred to the air or fuel gas.

The three chimney sections 8, 9 and l0 are separated by horizontal passages 11 and 12. These horizontal passages are made by placing the bricks 2 end to end ICC lengthwise of the regenerator and are placed so they are in vertical alignment with the lengthwise walls between the rows of chimneypassages shown in Figures l, 3 and 4 thus allowing gaseous flow from one section of chimneys to another. The chimneys of the three sections 8, 9 and 10 are shown staggered to each lengthwise of the regenerator and their crosswise walls biseet the gaseous flow from'one section to another. This staggering of chimneys and dust blowing passages l1 and 12 are fully `explained in my previous Patent #2,- 446,420 August 3, 1948.l The said patent shows all the chimney passages to be alike for the said' three sections in its drawings, but in this case refractory inserts are also used.

Figure 4 and top section 10 of Figure 2 show the assembling of the common bricks 2 of Figures 7 and 8 into the basket weave method of laying heat regenerator bricks.

The basket weave method is the only method used in the drawings for laying refractory bricks to make the chimneys in the heat regenerator when using either the common bricks 2 or the special bricks 1 shown in Figures 5 and 6 or the special bricks 14 shown in Figures `l4 and 15. 5

This invention shows an improvement by using a simple method for supporting refractory inserts in heat regenerators for open hearth or other regenerative furnaces where the temperature of the hot gases leaving the heat regenerator is too high for structural metal work and pivots for supporting the said inserts. Also this structural support in the horizontal bottom passage of a regenerative chamber where there is a rapid accumulation of dust would be an additional obstacle to the free ow of the hot waste gases and air and would cause the furnace to shut down more frequently for repairs than at present.

This construction is an improvement over the present pivot support for inserts in blast furnace stoves and similar apparatus.

Figures 1 and 2 show a new method of supporting refractory inserts-The refractory inserts 3 rest on the lugs of bricks yl. Brick 1 is shown in Figures 5 and 6 and the refractory insert 3 is shown in Figures 9 and l0.

Figure 1 is a plan view showing the laying of the first course of bricks 1 in the basket weave at the bottom of the chimneys 7 in section 8 of Figure 2. After this one course of bricks 1 are laid the rest of the chimneys 7 in section 8 are completed by using bricks 2 in the basket weave as shown in Figure 4 and top section 10 of Figure 2. The refractory inserts 3 are put in place as the chimneys are being built up. In the chimneys 7 of section 8 the said inserts are placed diagonally to the right as in Figure 1 so as to lie on the lugs of bricks l in the Figure 1.

The chimneys 6 of section 9 are built up in the same manner as those of section 8 except that the lugs of bricks 1 and the refractory inserts 3 are placed diagonally to the left as shown in the Figure 3. This places the inserts of section 9 at right angles to those inthe section 8.

The chimneys S of section 10 do not have inserts in them and are built by using only the common bricks 2 in the basket weave as shown in Figure 4 and the top section l0 of Figure 2.

The chimneys 5 are left more open than those below because the dirt gathers mostly on the top of the regenerator and is hard. It gets down into chimneys 5 and is hard at first but soon becomes less and softer. Much less dust gathers on the tops of the staggered ends of the chimneys 6 and in these chimneys at their top ends. It is easily removed by a dust blowing tool having a right angle bend on its end that is pushed along the dust Patented Oct. 7, 1958 blowing passages 12. The du'st is still less for section 8 and its chimneys 7. This dust is removed by same tool working in the horizontal dust blowing passages 11.

The fact that the dirt gathering is mostly in the vicinity of the top of the regenerator makes it possible to use refractory inserts in the regenerator of an open hearth furnace for a large part of its height and adds much to the heating surface of the regenerator.

There is a complete splitting of the gaseous flow by the staggered brick ends and also by the inserts from one'to the other for sections 8 and 9. ln the case of sections 9 and 10 the downward tlow of the hot gases from the hearth is completely split by the staggered brick ends of section 9 and partly by the inserts. In the case of the upward flow of the air from section 9 to section 10 the splitting of the air owis done only by the staggered bottom ends of section 10 and is complete.

The heat transfer rate is increased by the splitting of the flow because the heating surface comes into direct contact with the hot gases in the centre of the ow from the previous section. Similarly the heating surface comes into direct contact with the cold centre of the air ow from the previous section and the heat transfer rate for air is also increased.' The increased turbulence also causes an increase in the heat transfer rate.

The distribution of the vertical liow of both hot gases and air is also improved in the regenerator by the staggered chimney ends and the insert ends acting as a check on the excess ow of the hot gases to the stack end of the regenerator and the excess ow of the air to the hearth end of the regenerator. This improvement in distribution of vertical ow within the regenerator also helps to increase the heat transfer rate.

The draft loss for the hot gases is only a small part of the available stack draft and is more than taken care of by the internal dust blowing of the regenerator through holes in its stack end wall and the horizontal passages 11 and l2.

The draft loss for the air is taken care of by an increase in draft caused by higher air temperature and by cleaner chimneys.

The staggering in the heat regenerator may not be used4 if so desired. This would be more common in blast furnace stoves. When there is no staggering for regenerators of open hearth furnaces there should be at least one horizontal row of dust blowing passages such as 12 between sections 9 and 10 so as to blow the dust off the tops of the refractory inserts.

Figure 13 shows the application of the special refractory insert 13 as shown in Figures ll and 12. In Figure 10 it will beseen that the insert 3 does not go down into that part of the chimney surrounded by bricks l, while the special insert 13 does go down into that part in the bottom of the chimney and gives some more heating surface.

Figures 14 and l5 show brick 14 that has the same function as brick 1 taken twice so as to support a refractory insert having four rests in a chimney passage. This brick can be assembled in the basket weave so as to give 4 weave. The bricks 1 or 14 may be used several times throughout the height of a high chimney so as to distribute the load on several courses of special bricks having lugs.

The three distinct features of the invention are the application of refractory inserts to regenerators of regenerative furnaces, the method of supporting these inserts for regenerative furnaces or blast furnace stoves, and the new refractory inserts.

The sides of a refractory brick in the claims are the two sides exposed to the gaseous flow and are the side views of these bricks indicated in the drawings.

I claim: y

l. A checkerwork of transverse rows of refractory brick laid in courses to form vertical ues, the brick in one course having a pair of longitudinally spaced lugs on opposite faces running height-wise of the brick with the ends of the brick of each row abutting a side of a brick and a face of one lug of a brick in a transverse row, said pair of lugs being spaced so one lug engages a face of a brick in a transverse row and the other lug engages the opposite face of another brick in said row.

2. A checkerwork of transverse rows of refractory brick laid in courses to form vertical ues, the bricks in one course having a pair of longitudinally spaced lugs on opposite faces running height-wise of the brick, the lugs being offset in opposite directions from the longitudinal center line of the brick and spaced from each other a distance to engage opposite faces of bricks in a transverse row, the ends of the brick of each row abutting a side of a brick and a face of one lug of a brick in a transverse row.

3'. A checkerwork of transverse rows of refractory brick laid in courses to form vertical ues, the bn'ck in one course having spacing lugs on opposite faces running height-wise of the brick with the spacing of the lugs such that when the bricks are laid in courses with the ends of the brick of each row abutting the side of a brick and y the face of one lug of a brick in a transverse row, the

the necessary four lugs in the chimney passage as shown in the partial assembly of Figure 16 which is in the bottom of the chimney. The bricks 2 are used to complete the remainder of the chimney also in the same basket ues formed thereby are square shape with a pair of lugs projecting into the ues from opposite comers thereof.

4. A brick for checkerwork that is a parallelepiped having spacing lugs. on opposite faces running heightwise of the brick, the lugs being olset at opposite directions from the longitudinal center line of the brick and spaced from each other a distance to engage opposite faces of bricks in a transverse row.

References Cited in the file of this patent UNITED STATES PATENTS 656,138 Johnston Aug. 14, 1900 826,777 Ferguson July 24, 1906 935,372 Lamond Sept. 28, 1909 1,771,286 Brassert et al. July 22, 1930 1,815,905 Grilli et al. July 28, 1931 1,880,011 Boynton Sept. 27, 1932 FOREIGN PATENTS 372,632 Great Britain May 12, 1932 389,881 Great Britain Mar. 30, 1933 113,755 Australia Aug. 26, 1940 67,942 Norway June 12, 1944 

